<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>打印倒正金字塔直线</title>
	</head>
	<body>
		<script type="text/javascript">
			for(var i=100;i>=10;i-=10){
				document.write("<hr color='blue' width="+i+"px/>");
			}
			for(var i=20;i<=100;i+=10){
				document.write("<hr color='red' width="+i+"px/>");
			}
			
		</script>
	</body>
</html>
